[Diy_efi] P&H vs. sat (was: Diy_efi Digest, Vol 21, Issue 1)

[ScottyGrover at aol.com]

In a message dated 11/3/2006 2:16:26 P.M. Pacific Standard Time,  
espresso_doppio at yahoo.com writes:

---  ScottyGrover at aol.com wrote:

> Peak-and-hold injectors (at least the  ones I have
> had dealings with) ran in series electrically with
>  resistors which increased the resistance and lowered

> the required  current in the circuit so as not to
> increase the drain on the power  transistors in the
> control box.

I am so used to thinking in  sequential port injection
that I often forget about batch and bank  fire
applications.  You can certainly run several
low-impedance  injectors in series to allow triggering
of a bank-fire setup with only one  "channel" per bank,
thus lowering the cost and heat output of the ECU  (I
don't think anyone does this any more in production
vehicles, but it  is entirely possible that it was done
on the Jag back in the day, offering  the option of
using the stock injectors in a P&H setup with  a
sequential fire ECU that would allow a lot of engine
modification  without having to upgrade the injectors
themselves).

You can get the  same effect by running several
high-impedance injectors in parallel, and  then wiring
up such groups serially, so the resistance across the
whole  chain is the same as in a single high-impedance
injector; the more  injectors you add like that,
though, the more sluggish the individual  injectors
will be (since voltage is being split up between the
parallel  groups of injectors); I wonder if using caps
on the battery side of the  injectors would help with that?




The systems I was referring to were sequential systems (Type 3 VW, Datsun  
240Z)
Scotty